Coated granules



C. P. McNElL.

COATED GRANULES.

APPLICATION FILED APILzI. I9I9.

. ,42 l 2? l I Patented June 27, 1922.

DRUM

IIIIIII 1 l I-IoPPER.

CLAUDE MCNEIL, 0F NEW YORK, N. Y.

COATED GRNULES.

Applicatidn led April 21, 1919. Serial No. 291,585'.

To all whom 'it may concern:

Be it known that I, CLAUDE P. McNniL, a citizen of the United States, and residing at New York city, New York, have invented certain new and useful Improvements in Coated Granules, of which the following is a specification.

This invention relates to the spraying of granules and has for its object the production of a granule which is uniformly coated over its entire surface. In order to carry the objects of my invention into effect, I provide a process wherein chemicals in solution and liquids are sprayed over the granules.

My invention has been successfully applied to the coating of soda-lime with sodium permanganate. Permanganate coated soda-lime has been found useful for the 'absorption of certain gases used in warfare and encountered in the industries, such as arsine, phosgene and other chlorinated or,- ganic compounds, CO2 gas and the like. Formerly, the sodium perinanganate solution was incorporated in the granule during the` process of formation of the same but, since the yield of granules of the required size is only about 40% of the total weight of impregnated soda-lime, of the permanganateused was lost together With the rejected fines. The permanganate is comparatively expensive While the other ingredients are eomlmratively cheap, hence, the building up of 'the granule Without the permanganate and adding the permanganate after the fines have been removed, effects a great saving in permanganate. This procedure may be applied to a variety of substances and has been adapted to the spraying of soda-lime granules With permanganate, Navy soda-lime with Water, in the application of various chemicals such as copper sulphate, formaldehyde, caustic soda, etc., to charcoal granules, and many others.

A typical form of apparatus used in the.

ber (1).

Specification of Letters Iatent. Patnted Juin@ 28', 1922. l'

ing chamber andr provided with stationary Y hoods (2) and (3) at each end.V A feed hopper (4) 1s provided at one end of the cylinder to which is,v attached a chute (5) lead` pile up at any point.

The spraying fluid is 'supplied from a suitable source through the supply pipe (7) to Vthe tank (8) from which it is drawn through the pipes (9) and (10) and de- -livered through the spray nozzles or atomizers (1l) and (12) into the sprayingchami Com ressed air or other gas may be supplied throughthe pipe (13) to the tank (8) in order to aid the forcing of the spraying Huid out from the tank (8) through the nozzles (11) and (12).

The cylinder or drum (1) is preferably inclined as shown in Fig. 2, the portion of the cylinder Where the granules enter same spreading the granules so that they Will not being higher than the discharge end.' lotary motion is imparted to the, lcylinder (1) /by means of the motor (14),;belt (15)',

shaft (1G), gears (17) and racks (18). As this cylinder revolves the hoods (2) and remain stationary. The granules Within the cylinder are tumbled and agitated by the revolution of the cylinder (1) and the agitation may be increased by providing the interior ofthe cylinder 1) with baffle plates (19). As the cylinder (1) rotates the granules gravitate toward the discharge end and pass into the hopper (20). A plurality of atomizers are. usually-pro vided at each end of the cylinder, and they are so mounted that they can be directed into the chamber at any angle, thus giving considerable flexibility in operation. As the cylinder (1) revolves the granules are tu1n bled and rolled overand some are dropped through the spray. It will Le seen: v.that the granules as theyare fed from the hopper through the chute (5) into Vthe spraying chamber (1) pass through the jets of spraying Huid issuing fromV the Vnozzles- (11) This facilitates the uniform spraying of the granules. y

lThe process consists essentially in exposing the granules to an atomized spray of the liquid by both dropping the granules through a spray and spraying the liquid directly upon the granules which are being agitated in a suitable tumbling mechanism. The operation is continuous and the resulting product is uniformly coated due to the agitation and consequent exposure of all the surfaces of the granules to the liquid spray vwhich is in such a finely divided state that it is practically vaporized.

Although I have described specifically the spraying of soda-lime with permanganate solution, I do not intend that my invention be limited to this nor even to the other examples mentioned but desire to claim my invention broadly except as limited by the following claims:

l. Granules having their surfaces substantially uniformly coated With a permanganate.

2. Soda-lime granules having their surfaces substantially uniformly' coated with a salt.

3. Soda-lime granules having their surfaces substantially uniformly coated with an oxidizing salt.

4. Soda-lime granules having their surfaces substantially1 uniformly coated with a permanganatc.

CLAUDE P. MCNEIL.' 

